In the field of power semiconductor technology, it is desirable to provide semiconductor devices with protection mechanisms that prevent destruction of the semiconductor devices under extreme switching conditions. Such extreme switching conditions arise because power semiconductor diodes are operated in commutation mode. When operated in commutation mode, high electric fields can occur, for example at the n−n junction of a pn−n semiconductor diode, which can lead to an avalanche-like generation of charge carriers at the n−n junction. At the same point in time, high electric field strengths can occur at the pn junction of the pn−n semiconductor diode and lead to an avalanche-like generation of charge carriers at the pn-junction. The avalanche-like generation of charge carriers (so-called “avalanche generation”) results in an inability to maintain the high electric field blocking capability of the semiconductor diode in the n−-doped central region of the semiconductor diode. The semiconductor diode thus loses its blocking capability and is destroyed unless external measures for limiting current and power have been implemented.
In order to avoid destruction of the semiconductor diode, the commutation process of the diode can be slowed down. When using such semiconductor diodes within insulated gate bipolar transistor (IGBT) semiconductor modules, however, such a slow down can result in an increase in the switch-on losses of the IGBT. Other measures might lead to increased on-state or switching losses. Thus, there exists a need for an improved semiconductor device.